The Effect of Stimulus Size on the Reliable Stimulus Range of Perimetry

Purpose: Automated perimetry uses a 3.5 log unit (35dB) range of stimulus contrasts to assess function within the visual field. Using 'Size III' stimuli (0.438), presenting stimuli within the highest 15dB of available contrast may not increase the response probability at locations damaged by glaucoma, due to retinal ganglion cell response saturation. This experiment examines the effect of instead using 'Size V' (1.728) stimuli. Methods: Luminance increment thresholds for circular spot stimuli of each stimulus size were measured in 35 participants (mean deviation À20.9 to À3.4 dB, ages 52-87) using the method of constant stimuli, at four locations per participant. Frequency-ofseeing curves were fit at each size and location, with three free parameters: mean, standard deviation, and asymptotic maximum response probability. These were used to estimate the contrasts to which each participant would respond on 25% of presentations (c25). Results: Using segmented orthogonal regression, the maximum observed response probabilities for size III stimuli began to decline at c25 ¼ 25.2 dB (95% confidence interval 23.3-29.0 dB from bootstrap resampling). This decline started at similar contrast for the size V stimulus: c25 ¼ 25.0dB (22.0-26.8 dB). Among locations at which the sensitivity was above these split-points for both stimulus sizes, c25 averaged 5.6 dB higher for size V than size III stimuli. Conclusions: The lower limit of the reliable stimulus range did not differ significantly between stimulus sizes. However, more locations remained within the reliable stimulus range when using the size V stimulus. Translational Relevance: Size V stimuli enable reliable clinical testing later into the glaucomatous disease process

Predicting Progressive Glaucomatous Optic Neuropathy Using Baseline Standard Automated Perimetry Data

PURPOSE. To test the hypothesis that specific locations and patterns of threshold findings within the visual field have predictive value for progressive glaucomatous optic neuropathy (pGON). METHODS. Age-adjusted standard automated perimetry thresholds, along with other clinical variables gathered at the initial examination of 168 individuals with high-risk ocular hypertension or early glaucoma, were used as predictors in a classification tree model. The classification variable was a determination of pGON, based on longitudinally gathered stereo optic nerve head photographs. Only data for the worse eye of each individual were included. Data from 100 normal subjects were used to test the specificity of the models. RESULTS. Classification tree models suggest that patterns of baseline visual field findings are predictive of pGON with sensitivity 65% and specificity 87% on average. Average specificity when data from normal subjects were run on the models was 69%. CONCLUSIONS. Classification trees can be used to determine which visual field locations are most predictive of poorer prognosis for pGON. Spatial patterns within the visual field convey useable predictive information, in most cases when thresholds are still well within the classically defined normal range. (Invest Ophthalmol Vis Sci. 2009;50:674 -680

Phase 3, Randomized, 20-Month Study of the Efficacy and Safety of Bimatoprost Implant in Patients with Open-Angle Glaucoma and Ocular Hypertension (ARTEMIS 2)

Objective- To evaluate the intraocular pressure (IOP)-lowering efficacy and safety of 10 and 15 µg bimatoprost implant in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT). Methods- This randomized, 20-month, multicenter, masked, parallel-group, phase 3 trial enrolled 528 patients with OAG or OHT and an open iridocorneal angle inferiorly in the study eye. Study eyes were administered 10 or 15 µg bimatoprost implant on day 1, week 16, and week 32, or twice-daily topical timolol maleate 0.5%. Primary endpoints were IOP and IOP change from baseline through week 12. Safety measures included treatment-emergent adverse events (TEAEs) and corneal endothelial cell density (CECD). Results- Both 10 and 15 µg bimatoprost implant met the primary endpoint of noninferiority to timolol in IOP lowering through 12 weeks. Mean IOP reductions from baseline ranged from 6.2–7.4, 6.5–7.8, and 6.1–6.7 mmHg through week 12 in the 10 µg implant, 15 µg implant, and timolol groups, respectively. IOP lowering was similar after the second and third implant administrations. Probabilities of requiring no IOP-lowering treatment for 1 year after the third administration were 77.5% (10 µg implant) and 79.0% (15 µg implant). The most common TEAE was conjunctival hyperemia, typically temporally associated with the administration procedure. Corneal TEAEs of interest (primarily corneal endothelial cell loss, corneal edema, and corneal touch) were more frequent with the 15 than the 10 µg implant and generally were reported after repeated administrations. Loss in mean CECD from baseline to month 20 was ~ 5% in 10 µg implant-treated eyes and ~ 1% in topical timolol-treated eyes. Visual field progression (change in the mean deviation from baseline) was reduced in the 10 µg implant group compared with the timolol group. Conclusions- The results corroborated the previous phase 3 study of the bimatoprost implant. The bimatoprost implant met the primary endpoint and effectively lowered IOP. The majority of patients required no additional treatment for 12 months after the third administration. The benefit-risk assessment favored the 10 over the 15 µg implant. Studies evaluating other administration regimens with reduced risk of corneal events are ongoing. The bimatoprost implant has the potential to improve adherence and reduce treatment burden in glaucoma

Optic nerve cavitations in glaucoma suspect and glaucoma patients

Purpose: Glaucoma is associated with structural changes of the optic nerve head such as deformation, lamina cribosa defects, prelaminar schisis, and peripapillary retinal schisis. We describe optic nerve cavitations that were detected by routine spectral domain optical coherence tomography (OCT). Observations: OCT imaging showed cavitations in 5 eyes of 4 patients with an initial diagnosis of glaucoma or glaucoma suspect. The cavitations were seen as hyporeflective spaces that are sharply delineated from surrounding tissue. They were centered inferonasally, anterior to the lamina cribosa, and at least partially within the Bruch's membrane opening (BMO). They extended from 3 to 6 clock hours. Conclusion: AND IMPORTANCE: We describe a new OCT finding in patients with a diagnosis of glaucoma and glaucoma suspect. While previous reports describe cavitations in the choroid in patients with pathological myopia, our patients had minimal refractive error and the cavitations were located within the optic nerve. We will examine these patients over time to determine the impact of this finding on longitudinal changes in structure and function

The association between glaucoma treatment adherence with disease progression and loss to follow-up

Abstract Prospective cohort study from Brazil to evaluate glaucoma treatment adherence using a medication event monitoring system (MEMS) device and correlate with glaucoma progression and loss to follow-up (LTF) after one year of follow up. We included primary open glaucoma (POAG) patients treated with at least one ocular hypotensive eye drop. MEMS devices was used to monitor adherence for 60 days and evaluate the percentage of doses prescribed taken within the 60-day period. We classified patients according to rates of adherence: low adherence (less than 75% from MEMS measurements) and high adherence (more than 75% from MEMS measurements). We applied a questionnaire to investigated self-reported behavior towards treatment behaviors (glaucoma treatment compliance assessment tool, GTCAT). We also correlated rates of treatment adherence with clinical, demographical variables and the occurrence of glaucoma progression or LTF after one year of observation. We included 110 POAG patients and found that 28.18% of them were considered low adherent. We identify several variables associated with poor adherence such as glaucoma progression, LTF, younger age, low educational and income levels, absence of health insurance, years of disease and peak intraocular pressure. Several constructs from the self-reported GTCAT were also correlated with the rates of treatment adherence. To date, this is the first study in Latin America to evaluate glaucoma treatment adherence with MEMS devices and correlate adherence rates with glaucoma progression and LTF. We found a low-adherence rate of 28.18% and several additional risk factors were statistically associated with poor adherence

Primary Open-Angle Glaucoma Preferred Practice Pattern(®) Guidelines

PRIMARY OPEN-ANGLE GLAUCOMA PREFERRED PRACTICE PATTERN® Evidence-based update of the Primary Open-Angle Glaucoma Preferred Practice Pattern® (PPP) guidelines, describing the diagnosis and management of patients with primary open-angle glaucoma with an algorithm for patient management and detailed recommendations for evaluation and treatment options

Primary Angle Closure Preferred Practice Pattern(®) Guidelines

PRIMARY ANGLE CLOSURE PREFERRED PRACTICE PATTERN® Evidence-based update of the Primary Angle Closure Preferred Practice Pattern® (PPP) guidelines, describing the diagnosis and management of patients with primary angle closure with detailed recommendations for evaluation and treatment options

Causes of Visual Impairment and Common Eye Problems in Northwest American Indians and Alaska Natives

Objectives. Little information exists regarding the causes of visual impairment and the most common eye problems in American Indians/Alaska Natives. Methods. We randomly sampled American Indians/Alaska Natives older than 40 years from 3 tribes within the Northwest region. Results. We found a higher prevalence of visual impairment and normal-tension glaucoma, as well as a lower prevalence of ocular hypertension, in American Indians/Alaska Natives compared with previous results in other racial/ethnic groups. Conclusions. American Indians/Alaska Natives have a need for vision correction. Future interventions in American Indians/Alaska Natives should include providing spectacles for refractive error, detecting glaucoma, and preventing visual impairment from age-related maculopathy and cataracts

Primary Open-Angle Glaucoma Suspect Preferred Practice Pattern(®) Guidelines

PRIMARY OPEN-ANGLE GLAUCOMA SUSPECT PREFERRED PRACTICE PATTERN® Evidence-based update of the Primary Open-Angle Suspect Glaucoma Preferred Practice Pattern® (PPP) guidelines, describing the diagnosis and management of patients with primary open-angle glaucoma suspect with detailed recommendations for evaluation and treatment options